4 Structuring transmissions - broadcast disksSendercyclic repetition of data blocksdifferent patterns possible (optimization possible only if the content is known)Receiveruse of cachingcost-based strategy: what are the costs for a user (waiting time) if a data block has been requested but is currently not cachedapplication and cache have to know content of data blocks and access patterns of user to optimizeABCflat diskABCskewed diskABCmulti-diskProf. Dr.-Ing. Jochen Schiller, MC SS02 6.4

17 Multimedia Object Transfer Protocol (MOT)Problembroad range of receiver capabilities audio-only devices with single/multiple line text display, additional color graphic display, PC adapters etc.different types of receivers should at least be able to recognize all kinds of program associated and program independent data and process some of itSolutioncommon standard for data transmission: MOTimportant for MOT is the support of data formats used in other multimedia systems (e.g., online services, Internet, CD-ROM)DAB can therefore transmit HTML documents from the WWW with very little additional effortProf. Dr.-Ing. Jochen Schiller, MC SS